Recent activity

The geomagnetic field was quiet on June 1. Solar wind speed
ranged between 334 and 361 km/s (average speed was 348 km/s, increasing 34 km/s
over the previous day).

Solar flux measured at 20h UTC on 2.8 GHz was 79.4. The planetary A index
was 6 (STAR Ap - based on the mean of three hour interval ap
indices: 6.1). Three hour interval K indices: 22111222 (planetary),
22122223 (Boulder).

The background x-ray flux is at the class B1 level.

At midnight there were 3 spotted regions on the visible solar disk. The solar flare activity
level was moderate. A total of 1 C and 3 M class events were recorded during the day.

Region 10958 regained a single spot.
New region 10959 emerged in the southeast quadrant.
New region 10960 rotated into view at the southeast limb. This is a
complex region capable of producing further M class flares. There is a magnetic
delta structure in the northern central part of the largest trailing penumbra.
Polarity intermixing is evident other places in the region as well.
Flares: M1.0 at 06:51, M2.8 at 14:59, M2.1
at 21:52 and C2.8 at 22:22 UTC.

Coronal mass ejections (CMEs)

May 30 - June 1: No obvious fully or partially Earth directed CMEs were
observed in LASCO imagery.

Coronal holes

A recurrent coronal hole (CH271) in the southern hemisphere was in an Earth facing position on May 30-31.

Processed STEREO 195 image at 21:15 UTC on June 1. The
darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is
expected to be quiet to active on June 2-3 due to effects from CH271 and quiet
to unsettled on June 4.

Coronal holes (1)

Coronal mass ejections (2)

M and X class flares (3)

1) Effects from a coronal hole could reach Earth
within the next 5 days. When the high speed stream has arrived the
color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96
hours.
3) There is a possibility of either M or X class flares within the next
48 hours.

Propagation

Daily monitoring will not resume until a local noise problem (related to
construction work on a neighboring property) has been fixed. Occasional
monitoring reports will be submitted when propagation is good.

April 8, 2007: Stations from the Canadian Atlantic provinces had strong
signals during the night. Some stations from the northeastern USA and from
Florida did well too, in particular 1510 WWZN was impressive.

Data for all numbered solar regions according to the Solar Region
Summary provided by NOAA/SEC. Comments are my own, as is the
STAR spot count (spots observed at or inside a few hours before
midnight) and data for regions not numbered by SEC or where SEC has
observed no spots.
SEC active region numbers in the table below and in the active region
map above are the historic SEC/USAF numbers.

Active region

Date numbered

SEC
spot
count

STAR
spot
count

Location at midnight

Area

Classification

Comment

10958

2007.05.29

4

1

S13E22

0010

BXO

classification was AXX at midnight

10959

2007.06.01

2

4

S12E49

0010

BXO

classification was DSO at midnight, area 0030.
Location: S10E47

10960

2007.06.01

5

15

S06E73

0320

DKI

beta-gamma-delta
classification was EKI at midnight, area 0450

S703

2007.05.22

S09W54

plage

Total spot count:

11

20

SSN:

41

50

Monthly solar cycle data

Month

Average solar
flux at Earth

International sunspot number

Smoothed sunspot number

2000.04

184.2

125.5

120.8
cycle 23 sunspot max.

2000.07

202.3

170.1

119.8

2001.12

235.1

132.2

114.6 (-0.9)

2006.04

89.0

30.2

17.1 (-0.3)

2006.05

80.9

22.3

17.3 (+0.2)

2006.06

76.5

13.9

16.3 (-1.0)

2006.07

75.7

12.2

15.3 (-1.0)

2006.08

79.0

12.9

15.6 (+0.3)

2006.09

77.8

14.4

15.6 (+0.0)

2006.10

74.3

10.4

14.2 (-1.4)

2006.11

86.3

21.5

12.7 (-1.5)

2006.12

84.5

13.6

(12.1 predicted, -0.6)

2007.01

83.3

16.9

(11.7 predicted, -0.4)

2007.02

77.7

10.6

(11.1 predicted, -0.6)

2007.03

72.2

4.8

(10.7 predicted, -0.4)

2007.04

72.4

3.7

(10.9 predicted, +0.2)

2007.05

74.4

11.7

(11.0 predicted, +0.1)

2007.06

79.4 (1)

1.4 (2)

(11.3 predicted, +0.3)

1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (NOAA/SEC)
sunspot number. The official international sunspot number is typically
30-50% lower.

This report has been prepared by Jan
Alvestad. It is based partly on my own observations and analysis,
and
partly on data from some of these solar data sources.
All time references are to the UTC day. Comments and suggestions are
always welcome.